1. Field of Invention
The present invention relates to a terminal box apparatus for use in a solar cell module disposed on a roof of a house or the like. The present application claims priority to Japanese Application No. 2002-108077, filed on Apr. 10, 2002.
2. Description of Related Art
A solar-electric system for generating electricity by utilizing sunbeams by mounting a plurality of solar cell modules in the shape of a matrix on the roof of a house is known. In the solar-electric system, each solar cell module has a connection terminal box apparatus for connecting the solar cell module to other solar cell modules.
FIG. 15 shows a schematic construction of a conventional solar cell module 1. The solar cell module 1 has a large number of solar cells 3 (group 4 of cells) arranged oil a surface thereof, with the solar cells 3 electrically connected in series.
A terminal box apparatus 5 is disposed on a rear surface of a body 1 a of the solar cell module 1. As shown in FIG. 17, the terminal box apparatus 5 accommodates bypass diodes 6 serving as a bypass rectifying element. The bypass diodes 6 are connected in a direction reverse to parallel output voltages of the group 4 of cells to bypass the electric current of the inversely biased group 4 (or module 1) of the cells.
As shown in FIG. 16, one of two module connection cables 7 taken out of the terminal box apparatus 5 installed on the rear surface of the solar cell module 1 can be connected to the other of the two module connection cables 7 of the other solar cell module 1. A plurality of the solar cell modules 1 arranged in parallel on a roof or the like can connected sequentially in series.
In taking out an electric power from each solar cell module 1, as shown with the block diagram of FIG. 17, the solar cell modules 1 are electrically connected to construct a solar-electric system 9, and a plurality of the solar cell modules 1 connected sequentially in series is connected to an inverter or a connection box 10 to convert a direct current into an alternating current.
As shown in FIG. 18, the terminal box apparatus 5 has a box 12 formed by molding a synthetic resin. The box 12 has an approximately rectangular body 12a having an accommodation concavity and open on its upper surface. The box 12 also has a plate-shaped cover (not shown) mounted on an upper surface of the body 12a to close the accommodation concavity.
With reference to FIG. 18, a wiring hole 13 serving as a frame insertion hole is formed on the body 12a along one edge of a bottom surface of the body 12a. Cable insertion holes (right and left ends in FIG. 18) 14 through which a pair of the output take-out module connection cables 7 is inserted respectively are formed on side walls of the body 12a at the other side of the bottom surface of the body 12a. 
A plurality of terminal-fixing parts (not shown) is disposed in parallel at a part intermediate between the wiring hole 13 of the body 12a and the cable insertion holes 14, with the terminal-fixing parts (not shown in FIG. 18) projecting from the bottom surface of the body 12a in a right-to-left direction. A connection terminal 15 approximately T-shaped in a plan view is mounted on each terminal-fixing part by thermal crushing or the like. Side projected parts of the connection terminal 15 are projected in the right-to-left direction, whereas the central projected part thereof is projected toward the wiring hole 13.
An end of each of a plurality of connection elements (lead frame, not shown) connected to photoelectric conversion elements of the solar cell module 1 is inserted into the box 12 through the wiring hole 13 and soldered to the central projected part of the corresponding connection terminal 15.
The connection terminal 16 caulked to the end of the module connection cable 7 inserted through the cable insertion hole 14 is fastened to each of the connection terminals 15 at both ends of the box 12. The bypass diode 6 is soldered to projected parts of the adjacent connection terminals 15. As the bypass diode 6, a diode of mold type having a lead pin pulled to the outside is used. The lead pin is soldered to the projected parts. The bypass diodes 6 are connected in the direction reverse to parallel output voltages of the photoelectric conversion elements of each of the solar cell modules 1. Thereby the bypass diodes 6 have a bypass function.
In recent years, the solar cell 3 tends to be large, and electric current produced by the solar cell 3 also tends to be high. If the solar cell 3 is covered with leaves, the bypass diode 6 of the bypass circuit generates heat and its temperature rises. The higher output current is, the higher the temperature of the bypass diode 6 becomes. Thus, there is a possibility that the bearing life of peripheral component parts decreases.
The present invention has been made in view of the above-described problem. Accordingly, it is an object of the present invention to provide a terminal box apparatus for a solar cell module having improved durability and reliability for long-term service.
To achieve the object, in various exemplary embodiments, there is provided a terminal box apparatus for a solar cell module having a box mounted on the solar cell module; a plurality of connection terminals disposed inside the box and connected to a plurality of connection elements extending from photoelectric conversion elements of the solar cell module; a pair of output take-out module connection cables having one end thereof connected to one of the connection terminals and other end thereof pulled out of the box respectively; and a plurality of bypass rectifying elements extending across the adjacent connection terminals respectively.
Each of the bypass rectifying elements has a body and a pair of parallel lead plates disposed on an upper and lower surfaces of the body of the rectifying element and extended in opposite directions; each of the lead plates has a wide heat radiation part at an extended side thereof; and each of the heat radiation parts is soldered to a heat radiation part receiving piece projected from each of the connection terminals in a layered state.
In a terminal box apparatus for a solar cell module in various exemplary embodiments, one of the lead plates has a thickness less than 0.1 mm; and in the neighborhood of a portion in which the body of the rectifying element is connected to the other of a pair of the lead plates, a slit-shaped notch is formed in a direction vertical to an extension direction of the lead plate by cutting the lead plate alternately from both side surfaces thereof in the extension direction.
In a terminal box apparatus for a solar cell module in various exemplary embodiments, a heat radiation plate is interposed between the heat radiation part of the lead plate and the heat radiation part receiving piece of the connection terminal.
In a terminal box apparatus for a solar cell module in various exemplary embodiments, the connection terminal has a heat radiation surface part extended to a mounting surface of the box that is mounted on the solar cell module.
In a terminal box apparatus for a solar cell module in various exemplary embodiments, a metal plate is mounted at a portion of a mounting surface of the box, corresponding to a bypass rectifying element-mounting position, to be mounted on the solar cell module.
In a terminal box apparatus for a solar cell module in various exemplary embodiments, a surface of the box in contact with an air layer is made of metal, with the box installed on the solar cell module.
In a terminal box apparatus for a solar cell module in various exemplary embodiments, an entire outer surface of the box is covered with a metal cover.
In a terminal box apparatus for a solar cell module in various exemplary embodiments, the metal has superior heat radiation property.
In various exemplary embodiments, there is provided a terminal box apparatus for a solar cell module having a box mounted on the solar cell module; a plurality of connection terminals disposed inside the box and connected to a plurality of connection elements extending from photoelectric conversion elements of the solar cell module; a pair of output take-out module connection cables having one end thereof connected to one of the connection terminals and other end thereof pulled out of the box respectively; and a plurality of bypass rectifying elements extending across the adjacent connection terminals respectively.
The box includes a main box accommodating a pair of the output take-out module connection cables and a plurality of subsidiary boxes provided for the bypass rectifying elements respectively disposed across the adjacent connection terminals; and the connection terminals of the main box and the connection terminals of the subsidiary boxes are sequentially connected to each other with connection elements disposed at a side of the solar cell module.
In various exemplary embodiments, there is provided a terminal box apparatus for a solar cell module having a box mounted on the solar cell module; a plurality of connection terminals disposed inside the box and connected to a plurality of connection elements extending from photoelectric conversion elements of the solar cell module; a pair of output take-out module connection cables having one end thereof connected to one of the connection terminals and other end thereof pulled out of the box respectively; and a plurality of bypass rectifying elements extending across the adjacent connection terminals respectively. The bypass rectifying elements are disposed in a zigzag pattern.
In a terminal box apparatus for a solar cell module in various exemplary embodiments, heat insulation partitioning walls for partitioning the adjacent bypass rectifying elements from each other are provided.